Portable Elevated Platform with Locking Legs

ABSTRACT

A joint between a leg and an elevated platform includes a tapered receptacle with straight widening walls coupled to one of either the leg or the platform. A mating insert is coupled to the other of the leg or the platform and is selectively insertable into the tapered receptacle. The mating insert has straight narrowing walls that are engageable with the widening walls of the tapered receptacle. The weight of the platform pushes the insert into the receptacle such that the narrowing walls of the insert engage the widening walls of the tapered receptacle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is related to U.S. patent application Ser. No. ______, filed on Apr. 7, 2008, entitled “Portable Elevated Platform” as TNW Docket No. 00538-32686; and U.S. patent application Ser. No. ______, filed on Apr. 7, 2008, entitled “Telescoping Leg Lock and Portable Elevated Platform with Same” as TNW Docket No. 00538-32687; which are herein incorporated by reference in their entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to portable elevated platforms such as stages, risers, tables, chairs, scaffolding, and the like.

2. Related Art

Many portable elevated platforms such as stages, risers, tables, chairs, scaffolding and the like have removable or collapsible legs that can be configured to raise and support the platform at an elevation above a support surface such as the ground. Such legs may be attached to the platform in a variety of ways. For example, the legs may be attached to the platform by suitable removable fasteners such as screws, bolts and the like. These fasteners can be removed to detach the legs in order to take the platform down.

As another example, the legs are often pivotally connected to an underside of the platform and pivotal between a stowed position and an extended position. In the stowed position the legs are usually pivoted to rest against the table, with a longitudinal axis of the leg positioned parallel to the top of the platform, such that the leg does not raise the platform. In the extended position the leg is pivoted to extend away from the platform with the longitudinal axis of the leg positioned perpendicular to the top surface of the platform, such that the leg raises the platform. Additionally, many of these legs employ a locking mechanism to retain the leg in the extended position and prevent inadvertent collapse of the elevated platform.

Many portable elevated platforms, such as stages, risers, and scaffolding, are designed to be walked upon. Thus, the platforms and legs are subjected to dynamic loading as a person, or a group of people walk or stand on the platform. This dynamic loading can load and unload the interface between the legs and the platform which can cause the elevated platform to creak and rattle. Such racking noise during use is often not desirable, especially when the platform is being used for a performance, such as a play or choir recital. Additionally, the dynamic loading can cause slight movements in the leg-to-platform interface which can cause an unsteady feeling to people standing on the platform.

SUMMARY OF THE INVENTION

The inventors of the present invention have recognized that it would be advantageous to develop an elevated platform with a leg-to-platform interface that becomes more secure under loaded conditions. Additionally, the inventors of the present invention have recognized that it would be advantageous to develop a method and device for securing a leg to an elevated platform.

The invention provides a joint between a leg and an elevated platform. The joint can have a tapered receptacle with straight widening walls coupled to one of either the leg or the platform. A mating insert can be coupled to the other of the leg or the platform, and is selectively insertable into the tapered receptacle. The mating insert can have straight narrowing walls that are engageable with the widening walls of the tapered receptacle. The weight of the platform can push the insert into the receptacle such that the narrowing walls of the insert engage the widening walls of the tapered receptacle.

The present invention also provides for a method for positioning a leg to support a platform including moving the leg from a stowed position to a support position with respect to the platform. An insert on one of either the leg or the platform can be slid into a receptacle on the other of the leg or the platform. The insert can have narrowing walls that can engage corresponding widening walls in the receptacle.

Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a joint between a leg and a platform in accordance with an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the joint of FIG. 1;

FIG. 3 is perspective view of the joint of FIG. 1, shown with the leg in an extended support position;

FIG. 4 is a perspective view of the joint of FIG. 1, shown with the leg in a stowed position;

FIG. 5 is a perspective view of the joint of FIG. 1, shown with the leg in a stowed position; and

FIG. 6 is a cross section view of joint between a leg and a platform in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION

Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

The embodiments of the present invention described herein provide generally for a joint between a collapsible leg and support platform of a portable elevated platform such as a portable stage, riser, scaffold or the like. The joint can include a receptacle disposed on or integrally formed with either the leg or the platform. The receptacle can have straight widening walls extending from a terminal end adjacent either the leg or the platform to a relatively wider opening. The joint can also include an insert disposed on or integrally formed with the other of the leg or the platform. The insert can have straight narrowing walls extending from the other of the leg or the platform to a relatively narrower mating terminal end. The widening walls of the receptacle and the narrowing walls of the insert can be inclined at corresponding angles with respect to a longitudinal axis of the leg such that the inclined widening walls of the receptacle can engage the correspondingly inclined narrowing walls of the insert. The angle of the incline of the widening walls and the narrowing walls can assist in seating the platform on the leg. Additionally, the weight of the platform or a load placed upon the platform can push the widening walls of the insert onto the narrowing walls of the insert so as to secure the platform in an elevated position supported by the leg.

As illustrated in FIGS. 1-6, a joint, indicated generally at 10, between a leg 12 and a platform 14 (FIG. 2) in accordance an embodiment of the present invention shown for use in raising and collapsing a portable elevated platform such as a stage, riser, scaffold, and the like. The joint 10 can include a tapered receptacle, indicated generally at 40, and a mating insert, indicated generally at 60. In one aspect, the tapered receptacle 40 can be associated with the platform 14, and the mating insert 60 can be associated with the leg 12.

The tapered receptacle 40 can be formed in a platform corner support, indicated generally at 20. The corner support 20 can be formed of a structural material, such as a metal, or structural plastic. In one aspect, the corner support can be formed of steel or aluminum. In another aspect, the corner support 20 can be formed of a moldable structural plastic or polymer by a molding process such as rotational molding, injection molding, blow molding, casting, and the like.

The corner support 20 can have an upper surface 24 that can carry the platform 14. A flange 26 can extend upward from a peripheral edge 28 of the upper surface 24 to bound, protect, and align the corner, indicated generally at 16, of the platform 14. The corner support 20 can also have a plurality of ribs 30 and pockets or spaces 32 that can strengthen the corner support 20.

Additionally, the corner support 20 can have protrusions 34 extending away from sides 36 of the corner support 20. The protrusions 34 can be coupled to support structure, such as beams 38 (FIG. 2) that can extend between adjacent corner supports under the platform 14. The beams 38 can be configured to support and carry the platform 14. The corner supports 20, beams 38 and platform 14 can together form the platform.

The tapered receptacle 40 can be disposed on or formed in a bottom or lower surface 22 of the corner support 20. The tapered receptacle 40 can have straight widening walls 42 extending from a narrower terminal end 44 (FIG. 2) adjacent and below the upper support surface 24 to a wider opening 46 at a lower surface 22 of the corner support 20. The widening walls 42 can also be flat with a trapezoidal shape and the receptacle 40 can be formed four trapezoidal shaped flat walls connected side to side. The widening walls 42 of the tapered receptacle 40 can be disposed at an acute angle with respect to a longitudinal axis, indicated at dashed lines 18 (FIG. 2), of the leg 12 or the receptacle. In one aspect, the widening walls 42 of the tapered receptacle 40 can be disposed at an angle of approximately 15 degrees with respect to the longitudinal axis 18 of the leg 12 or the receptacle.

Referring to FIGS. 4-5, the tapered receptacle 40 can also include a keyway 48 formed in a sidewall 50 of the tapered receptacle 40. The keyway 48 can extend through the sidewall 50 and through the straight widening wall 42 corresponding to the sidewall 50 to form the keyway 48. The keyway 48 can be sized and shaped to receive the insert 60 when the leg 12 is positioned in a stowed position. The keyway 48 can have at least one hook 52 extending outward from the outer sidewall 50. In one aspect, the key way 48 can have two hooks 52. The hooks 52 can hold the insert 60 so as to restrict movement of the leg 12 with respect to the platform 14. In this way, the hooks 52 can hold the leg 12 in the stowed position.

Returning to FIGS. 1-5, the mating insert 60 can be disposed or formed on an end 8 of the leg 12. The leg 12 can be an elongated member having a longitudinal axis 18. Thus, the mating insert 60 can be coupled to an upper end 8 of the leg 12. The lower end 6 of the leg 12 can be configured to rest on a support surface such as the ground. In one aspect, the lower end 6 of the leg 12 can include a foot (not shown), or a further leg extension (not shown).

The leg 12 can be formed of a structural material with sufficient strength to support and carry the platform. For example, the leg 12 can be formed with a metal material, structural grade polymer material, structural composite material, and the like. In one aspect, the leg 12 can be formed of a metal such as steel or aluminum. In another aspect, the leg 12 can be formed of a structural plastic material by a molding process such as rotational molding, injection molding, blow molding, extrusion, casting, and the like.

The leg 12 can be pivotally coupled to the platform 14 and can pivot between a stowed position, as shown in FIGS. 4-5, and an extended support position, as shown in FIGS. 2-3. In the stowed position, the leg 12 can be positioned adjacent the platform 14 with the longitudinal axis 18 of the leg 12 extending substantially co planar with the top surface 15 of the platform 14. In the extended support position, the insert 60 can be disposed in the tapered receptacle 40 and the leg 12 can be oriented substantially perpendicular to the top surface 15 of the platform 14.

The mating insert 60 can have straight narrowing walls 62 extending from a wider end 64 coupled to the upper end 8 of the leg 12 to a narrower terminal end 66 that can be selectively insertable into the tapered receptacle 40. The narrowing walls 62 of the insert 60 can be inclined or angled at a corresponding angle to the angle of the widening walls 42 of the tapered receptacle 40. The narrowing walls 62 can also be flat and have a trapezoidal shape, and the insert 60 can be formed of four flat trapezoidal walls.

In one aspect, the narrowing walls 62 of the insert 60 can be inclined at an angle of approximately 15 degrees. In this way, the narrowing walls 62 of the mating insert 60 can mate with the widening walls 42 of the tapered receptacle 40, and can frictionally engage the widening walls 42 of the tapered receptacle 40 when the mating insert 60 is selectively inserted into the tapered receptacle 40. The 15 degree angle has been found to provide a sufficient locking force to secure the leg in the platform and reduce noise and wobble or play in the leg. Narrower angles have been found to provide too much locking force while greater angles have been found to provide insufficient locking force. Thus, an angle narrower than about 15 degrees make the leg difficult to disengage from the tapered receptacle, while an angle greater than about 15 degrees allows the leg to disengage or “cam out” of the tapered receptacle under a horizontal load applied to the platform.

The mating insert 60 can also have a flange 68 coupled to and extending from the narrower end 66 of the insert 60. The flange 68 can extend from the narrower end 66 of insert 60 away from the leg 12. The flange 68 can form a peripheral edge of an aperture 72 extending into the mating insert 60. In one aspect, the aperture 72 can extend into a hollow interior 74 (FIG. 2) of the leg 12.

When the leg 12 is in the extended support position, as shown in FIGS. 2-3, the aperture 72 can receive and enclose outer hinge brackets 90 coupled to the corner support 20 that extend into the tapered receptacle 40. The hinge brackets 90 can form a slot, indicated generally at 92, with a plurality of sidewalls 96 (FIG. 5) that extend from the corner bracket 20. The flange 68 on the insert 60 can extend into the slot 92 in the receptacle 40, and can help to secure the leg 12 from lateral motion with respect to the receptacle 40.

A pivot rod 100 can be slidably disposed inside the hollow interior 74 of the leg 12 such that the leg 12 forms an outer shell about the pivot rod 100. Thus, the pivot rod 100 can slide within the outer shell or leg 12 between an extended position, as best seen in FIG. 1, and a retracted position, as best seen in FIG. 2.

The pivot rod 100 can have a pivot end 102 that extends away from the leg 12. The pivot end 102 can be inserted between the outer hinge brackets 90 to form a pivot or hinge, indicated generally at 110 (FIG. 5), between the leg 12 and the corner support 20. The pivot end 102 can have a hole 104 and the hinge brackets 90 can have corresponding holes 98 that can be aligned with the hole 104 in the pivot end 102 when the pivot end is disposed between the outer hinge brackets. A pin 106 can be disposed through the holes 104 and 98 to allow the pivot end 102 of the pivot rod 100 to rotate or pivot around the pin 104. In this way, the mating insert 60 can be pivotally coupled to the tapered receptacle 40.

A biasing device, indicated generally at 130, can be coupled to the pivot rod 100 to bias the pivot rod to the retracted position. In one aspect, the biasing device 130 can be a spring 132, as shown in FIG. 2. The spring 132 can be coupled between the pivot rod 100 and leg 12 such that the leg can be pulled to extend the pivot rod 100 out of the leg to the extended position. With the pivot rod 100 in the extended position, the leg 12 can pivot, as shown in FIG. 1, between the stowed position, as shown in FIGS. 4-5, and the support position, as shown in FIGS. 2-3. In the stowed position, the biasing device 130 can pull the flange 68 of the insert 60 under the hooks 52 on the corner support 20 to secure the leg 12 in the stowed position. In the extended position, the biasing device 130 can bias the mating insert into the tapered receptacle 40, and the flange 68 into the hinge bracket 90, to secure the leg 12 against lateral movement with respect to the platform 14. In this way, the flange 68 can advantageously reduce the likelihood of an inadvertent collapse of the leg 12 when a load is placed on the platform 14.

The pivot rod 100 can also include a stop 108 coupled to an end 112 of the pivot rod 100 opposite the pivot end 102. The stop 108 can be sized and shaped to fit and slide within the hollow interior 74 of the leg 12. The stop 108 can also be sized to retain the pivot rod 100 in the outer shell or leg 12 when the pivot rod 100 is in the extended position.

In use, a portable elevated platform, such as a portable stage, riser, and the like, can be disposed on a support surface, such as the ground, such that a user has access to legs 12 stowed on an underside of the platform. A leg 12 can be grasped by the user and pulled to extend the pivot rod 100 out of the leg and to release the flange 68 on the leg from the hooks 52 on the platform 14. With the flange 68 free of the hooks 52, the user can pivot the leg 12 about the pivot or hinge 92 from the stowed position to the extended support position. The user can then repeat the extension and pivoting of any additional legs on the platform. When all of the legs are positioned in the support position relative to the platform, the platform 14 can be turned to position the legs 12 below the platform such that the legs support and carry the platform.

Advantageously, the weight of the platform 14 can push the mating insert 60 on the leg 12 into the tapered receptacle 40 such that the narrowing walls 62 of the insert 60 engage the widening walls 42 of the tapered receptacle 40 and secure the platform 14 from unwanted motion and noise due to movement of the platform against the legs. As an additional advantage, weight or loads placed on the platform 14 further push the narrowing walls 62 of the mating insert 60 against the widening walls 42 of the tapered receptacle 40 such that the angle of the widening and narrowing walls 42 and 62, respectively, helps to retain the insert 60 in the receptacle 40 even when the loads are dynamically changing on the platform 14.

As illustrated in FIG. 6, a joint, indicated generally at 200, is shown in accordance with another embodiment of the present invention for use in joining a collapsible leg to a portable elevated platform such as a stage, riser, scaffolding, or the like. The joint 200 can be similar in many respects to the joint 10 described above and shown in FIGS. 1-5. The joint 200 can include a tapered receptacle, indicated generally at 240, and a mating insert, indicated generally at 260. In this embodiment, the tapered receptacle 240 can be disposed on the leg 212, and the mating insert 260 can be disposed on the corner support 220. Thus, it will be appreciated that the tapered receptacle 240 can be disposed on one of either the leg 212 or the corner support 220, and the mating insert 260 can be disposed on the other of the leg 212 or the corner support 220, and that regardless of which configuration is used, the widening walls 242 of the receptacle 240 can engage the narrowing walls 262 of the insert 260 to secure the leg 212 in the extended position.

The present invention also provides for a method for positioning a leg to support a platform including moving the leg from a stowed position to a support position with respect to the platform. An insert on one of either the leg or the platform can be slid into a receptacle on the other of the leg or the platform. The insert can have narrowing walls that can engage corresponding widening walls in the receptacle.

The method can also include placing a load on the platform to secure the narrowing walls of the insert against the widening walls of the receptacle.

Additionally, the method can include sliding the insert away from the receptacle to disengage the narrowing walls of the insert from the widening walls of the receptacle. The leg can be moved from the support position to the stowed position.

It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention. While the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth herein. 

1. A joint between a leg and an elevated platform, comprising: a) a tapered receptacle having straight widening walls couplable to one of either the leg or the platform; b) a mating insert couplable to the other of the leg or the platform and selectively insertable into the tapered receptacle, the mating insert having straight narrowing walls engageable with the widening walls of the tapered receptacle; and c) weight of the platform pushing the insert into the receptacle such that the narrowing walls of the insert engage the widening walls of the tapered receptacle.
 2. A joint in accordance with claim 1, wherein the leg is pivotally coupled to the platform and is pivotal between a stowed position with the insert removed from the tapered receptacle configured to position the leg adjacent the platform, and a support position with the insert disposed in the tapered receptacle configured to orient the leg substantially perpendicular to the platform.
 3. A joint in accordance with claim 2, wherein the leg further comprises: a) an outer shell; b) a pivot rod slidably disposed in the outer shell with a pivot end extending away from the shell and pivotally coupled to the tapered receptacle, the pivot rod being slidable within the outer shell between an extended position and a retracted position; and c) a biasing device, coupled to the pivot rod to bias the pivot rod to retracted position.
 4. A joint in accordance with claim 3, wherein the pivot rod further includes a stop coupled to an end of the pivot rod opposite the pivot end, the stop being sized and shaped to retain the pivot rod in the outer shell when the pivot rod is in the extended position.
 5. A joint in accordance with claim 1, wherein the tapered receptacle further includes a keyway formed in a sidewall of the tapered receptacle, the keyway being sized and shaped to receive the insert when the leg is positioned in a stowed position.
 6. A joint in accordance with claim 1, wherein the widening walls of the tapered receptacle are disposed at an acute angle with respect to a longitudinal axis of the tapered receptacle and the narrowing walls of the insert are disposed at a corresponding angle to the widening walls.
 7. A joint in accordance with claim 1, wherein the widening walls of the tapered receptacle are disposed at an angle of approximately 15 degrees with respect to a longitudinal axis of the receptacle and the narrowing walls of the insert are disposed at a corresponding angle of approximately 15 degrees.
 8. A joint in accordance with claim 1, wherein the narrowing walls and widening walls center the insert within the receptacle and restrict movement of the insert with respect to the receptacle when a load is placed on the platform.
 9. A joint in accordance with claim 1, further comprising a platform with at least one leg, and wherein the receptacle is disposed on the leg and the insert is disposed on the platform.
 10. A joint in accordance with claim 1, further comprising a platform with at least one leg, and wherein the receptacle is disposed on the platform and the insert is disposed on the leg.
 11. A joint in accordance with claim 1, further comprising: a) a flange coupled to a narrower end of the insert; and b) a slot formed in a narrower end of the receptacle, the slot being sized and shaped to receive the flange.
 13. A joint in accordance with claim 1, wherein the widening walls of the tapered receptacle and the narrowing walls of the insert are substantially flat.
 14. A joint in accordance with claim 1, wherein the widening walls of the tapered receptacle and the narrowing walls of the insert have a substantially trapezoidal shape.
 15. A joint between a leg and an elevated platform, comprising: a) a platform with at least one leg; b) a tapered receptacle coupled to the platform and having straight widening walls extending from a terminal end adjacent an underside of the platform to a relatively wider opening; c) a mating insert disposed on the leg and selectively insertable into the tapered receptacle, the mating insert having straight narrowing walls extending from an end of the leg to a relatively narrower mating terminal end, such that the narrowing walls of the insert engage the widening walls of the tapered receptacle.
 16. A joint in accordance with claim 15, wherein the leg is pivotally coupled to the platform and is pivotal between a stowed position with the leg adjacent the platform and a support position with the insert disposed in the tapered receptacle and the leg oriented substantially perpendicular to the platform.
 17. A joint in accordance with claim 16, wherein the leg further comprises: a) an outer shell; b) a pivot rod slidably disposed in the outer shell with a pivot end extending away from the shell and pivotally coupled to the tapered receptacle, the pivot rod being slidable within the outer shell between an extended position and a retracted position; c) a biasing device, coupled to the pivot rod to bias the pivot rod to retracted position; and d) a stop coupled to an end of the pivot rod opposite the pivot end, the stop being sized and shaped to retain the pivot rod in the outer shell when the pivot rod is in the extended position.
 18. A joint in accordance with claim 15, wherein the tapered receptacle further includes a keyway formed in a sidewall of the tapered receptacle, the keyway being sized and shaped to receive the leg when the leg is positioned in a stowed position.
 19. A joint in accordance with claim 15, wherein the widening walls of the tapered receptacle are disposed at an acute angle with respect to a longitudinal axis of the leg and the narrowing walls of the insert are disposed at a corresponding angle to the widening walls.
 20. A joint in accordance with claim 15, wherein the widening walls of the tapered receptacle are disposed at an at an angle of approximately 15 degrees with respect to a longitudinal axis of the leg and the narrowing walls of the insert are disposed at a corresponding angle of approximately 15 degrees.
 21. A method for positioning a leg to support a platform, comprising: a) moving the leg from a stowed position to a support position with respect to the platform; and b) sliding an insert on one of either the leg or the platform into a receptacle on the other of the leg or the platform, the insert having narrowing walls engageable with corresponding widening walls in the receptacle.
 22. The method of claim 21, further comprising: placing a load on the platform to secure the narrowing walls of the insert against the widening walls of the receptacle.
 23. The method of claim 21, further comprising: a) sliding the insert away from the receptacle to disengage the narrowing walls of the insert from the widening walls of the receptacle; and b) moving the leg from the support position to the stowed position.
 24. The method of claim 21, wherein the receptacle has straight widening walls and the insert has straight narrowing walls selectively insertable into the receptacle.
 25. A joint between a leg and an elevated platform, comprising: a) a platform with at least one leg; b) a tapered receptacle having straight, flat widening walls coupled to one of either the leg or the platform; c) a mating insert coupled to the other of the leg or the platform and selectively insertable into the tapered receptacle, the mating insert having straight, flat narrowing walls engageable with the widening walls of the tapered receptacle; d) the insert being removably insertable into the receptacle such that the narrowing walls of the insert engage the widening walls of the tapered receptacle; and e) a pivoting rod extending between the tapered receptacle and the mating insert, and pivotally coupling the leg to the platform with the leg being pivotal between: i) a stowed position with the insert removed from the tapered receptacle; and ii) a support position with the insert disposed in the tapered receptacle. 